The first electronic mail systems used file transfer protocols where the recipient's address was in the first line of a message sent as a file. More elaborate electronic mail systems have been defined and described in RFC (Request For Comments) documents. Electronic mail transmission protocols have been standardized such as the Simple Mail Transfer Protocol (SMTP), RFC 2821 and the Internet Message Format RFC 2822. According to the SMTP model, the sender of a message/electronic mail provides in addition to the normal text, additional information which are sent in the header of the message. The author of the message/electronic mail indicates:                a sender address (“From:” field in the mail header),        a recipient address which may be the address of final recipient (“To:” field),        the address of the persons to be copied (“Cc:” field), and        the address of persons to be on “Blind Carbon Copy” (“Bcc:” field).        
The “Bcc:” field comprises the address of the recipients of the message/electronic mail whose address must not be revealed to the other recipients of the message. There are three ways in which the “Bcc:” field is used (refer to Internet Message Format RFC2822):                In the first case, when a message comprising a “Bcc:” field is prepared to be sent, the “Bcc:” line is removed even though all of the recipients (including those specified in the “Bcc:” field) are sent a copy of the message.        In the second case, a copy of the message with the “Bcc:” line removed as above, is sent to the recipients specified in the “To:” and “Cc:” lines. However, the recipients on the “Bcc:” line get a separate copy of the message with a “Bcc:” line (When there are multiple recipient addresses in the “Bcc:” field, as in some implementations, the “Bcc:” line comprises only the address of the recipient).        Finally, since a “Bcc:” field may contain no address, a “Bcc:” field can be sent without any addresses indicating to the recipients that blind copies were sent to others.        
SMTP, by introducing the recipient fields “To:”, “Cc:” and “Bcc:” takes into account the need to perform two operations:                sending an electronic mail to one or several primary recipients (“To:” field), officially informing other recipients of the electronic mail (the “Cc:” field), and        independently and unofficially informing other recipients of the electronic mail (the “Bcc:” field).        
SMTP can send electronic mails to these three categories of recipients without duplicating the sending operations. SMTP proposes a function for simplifying the management of the addresses, mainly based on the concept of Directories and Distribution Lists.                Directories can be based either on a general shared Directory or on Local Address Books. Directories comprise distribution lists to facilitate sending to multiple recipients. According to SMTP, a mailbox is a virtual storage entity which receives electronic mail for a particular recipient.        A Distribution List allows a sender to name a group of recipients without actually providing an individual mailbox address for each recipient. When creating electronic mail, the sender enters the name of the distribution list.        In the case of a local distribution list, the mail application operating on the workstation automatically expands the distribution list by replacing the distribution list name by the address of each member of the distribution list.        If the distribution list is not local, the distribution list name is inserted in the list of recipients. The distribution list will be expanded by a Mail Transfer Agent (MTA) owner of this distribution list.Therefore, the header of the message/email may comprise both a list of mail box addresses and distribution list names.        
It is possible for the searcher to request (or not) a mail acknowledgment from the recipients.
Electronic mail is used to pass information to other recipients and to request answers to questions. For example in a virtual enterprise or in a consortium, the prime partner may request that other partners complete a form concerning their enterprise in order to reply to a request for information from a customer. Answers generally have to be received as soon as possible. A way to track the received responses and hence the responses which are not yet received, is to follow a manual tracking process. Moreover to locate electronic mail recipients, the originator of the electronic mail must forward the initial mail to the recipients who have not yet answered. This method is not user friendly as in a forward action, the fields “To:”, “Cc:” and “Bcc:” are initially set to blank and have to be filled by the originator of the mail. In the forwarded electronic mail, a hunt out text also has to be added. If the originator decides to hunt out or locate electronic mail recipients individually and to not reveal the locator to the other partners who have not yet responded, the process may become very long, error prone and tedious.
U.S. Patent Application US 2004/0249890, entitled “Method and System for Notification of Electronic Message Reply Requirements” (Fellenstein et al.), discloses a new function within electronic mail applications whereby documents or messages, which are annotated or designated with a notification such as “reply requested”, are monitored by a new proactive reminder system, in order to minimize the occurrence of late responses. In Fellenstein et al., a new selection is added to the menus to “enable reminder function”. In the process of this invention, the sender enables the reminder function. The sender then selects the date and time to send a first reminder, (if response has not been received). The sender then selects frequency of reminder after the reminder is sent, (every 8 hours for example). The sender can choose to be notified or excluded from reminders. A sender may also choose to be notified, at the reminder interval, that responses have not yet been received. However, in the case where the audience of the note is very large, the user may wish for reminders to be sent to recipients, but not to be copied on these reminders. The method modifies both the sender and the receiver mail client applications. The mail application on the sender side is modified by adding a request reply tag with associated metadata such as the periodicity of reminding, the date of the first reminder, etc. . . . The mail application on the receiver side is also modified by enabling a function aimed to perform a periodic notification which reminds the recipient of an electronic message about the need to reply to the received message. This method allows a selective request to a reply to a subset of recipients but does not provide an efficient method to manage the responses. The main drawback of this solution is the need to implement the invention with all receivers to whom a reply is requested.